Email applications commonly store and display information about a user's personal contacts. The email applications permit a user to enter, modify and display the contact information on an input device. Ideally, each contact stored in an email application corresponds to a single person. However, often multiple contact records are entered for the same person.
In addition to email applications, contact information may be derived from other sources. For example contact information may be found in electronic documents and from third parties, such as social networking applications. When displaying contact information from multiple sources on the input device, duplicate contact information may sometimes be displayed.